Planning exercises suggested that in an emergency, up to three years' supply of antibiotics could be used in a month, he warned.

'Manufacturers cannot suddenly increase supply but one way of dealing with that is to have a buffer store,' he said.

Once a buffer stock has been established, new stock can simply be added as supplies are used to retain sufficient in-date supplies of drugs.

The distribution of medicines might also be affected during an emergency, he added. 'Companies wouldn't stop manufacturing drugs, but you wouldn't have the distribution, or drivers might be ill.'

The DoH has published the full list of over 454 products, many listing several formulations or doses of the same drug.

The list includes drugs for epilepsy and schizophrenia as well as antibiotics and intravenous fluids.

Dr Beeby said that for some of the medicines, only small quantities would need to be stored. But, he added, the detail in the DoH plans suggested it was looking at the volumes required to maintain sufficient supply.

The Pharmaceutical Services Negotiating Committee said the establishment of buffer stocks was 'only part of the solution to a highly complex problem'.